The present invention relates to hydrocarbon catalytic cracking catalyst compositions and in particular relates to catalyst compositions suitable for fluid cat-cracking of heavy hydrocarbon oils such as residual oil and the like.
As hydrocarbon catalytic cracking catalysts, there have generally been employed those catalysts comprising dispersed crystalline aluminosilicates in silica inorganic oxide matrixes such as silica, silica-alumina, silica-magnesia, silica-zirconia, silica-titania and the like. In addition thereto, catalysts using alumina as the matrix have been introduced in technical documents.
In the crystalline aluminosilicate zeolite-containing catalytic cracking catalysts mentioned above, it is generally said that the catalytic activity and selectivity to the C.sub.5.sup.+ fraction of the catalyst can be enhanced by increasing the content of crystalline aluminosilicate zeolite. However, the increased amount of the crystalline aluminosilicate zeolite has a tendency to deteriorate the mechanical strength and weaken the attrition resistance of the catalyst particles. Accordingly, it has been customary in the enhancing of the activity and selectivity of the catalyst by increasing the content of the crystalline aluminosilicate zeolite, to adopt the steps of using silica sol (which see U.S. Pat. No. 4,022,714) and silica-alumina sol, the aluminum phosphate solution or the aluminium chlohydro (see Japanese Laid Open Patent Application No. 36637/1983) as bonding agents for the crystalline aluminosilicate zeolite. However, the fact is that as these usual bonding agents cover the surface of the crystalline aluminosilicate zeolite particles dispersed in the catalyst compositions densely, the cracking activity or selectivity of the catalysts can not be enhanced that much for the increased amount of crystalline aluminosilicate zeolite.
In view of this, the inventors of this application have proposed a method for preparing crystalline aluminosilicate zeolite-containing catalytic cracking catalyst compositions comprising peptizing pseudoboehmite with a suitable acid and using the same in place of the usual bonding agents, in the co-pending U.S. Ser. No. 811,617 filed Dec. 20, 1985 (now abandoned).
On the other hand, as the measure for improving the metals tolerance of the catalytic cracking catalysts, U.S. Pat. No. 4,430,199 discloses the step of containing a phosphorus component in a zeolite-containing catalytic cracking catalyst, and U.S. Pat. No. 4,183,803 teaches a catalytic cracking catalyst comprising dispersed zeolite in an alumino-aluminumphosphate-silica matrix. In addition, U.S. Pat. No. 3,711,422 describes that addition of an antimony compound to a catalytic cracking catalyst passivates metallic contaminants deposited on said catalyst, and U.S. Pat. No. 4,183,803 describes a process for passivating metallic contaminants by contacting the metallic contaminants-deposited catalyst with a compound of antimony, bismuth, phosphorus or the like. In addition, U.S. Pat. No. 4,222,896 describes a catalyst comprising dispersed zeolite in a MgO-Al.sub.2 O.sub.3 -AlPO.sub.4 matrix. And, the co-pending U.S. Ser. No. 808,414 filed Dec. 12, 1985 (now abandoned) proposes a catalytic cracking catalyst composition comprising alumina particles containing a phosphorus component and having a particle diameter of 2-60 .mu., a crystalline aluminosilicate zeolite and a porous inorganic matrix.